Emergency power supply device

ABSTRACT

The present invention provides an improved arrangement for supplying emergency power to a wind power installation. In the event of a power failure, sufficient emergency power may be supplied to reposition the rotor blades of the wind power installation and avoid damage to the overall system. This is done through the use of one or more capacitors. The capacitors may be charged with energy during the normal operation of the wind power installation and, in the event of a system failure, the energy stored within the capacitors may be used to provide emergency functions. In addition to repositioning the rotor blades, the stored energy may be used, for example, to rotate the wind power installation pod away from the wind and power emergency or auxiliary lighting systems.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention provides a unique arrangement for providingemergency power to a wind power installation, including the use of oneor more capacitors as a storage means for electrical energy.

[0003] 2. Description of the Related Art

[0004] In the known prior art, wind power installations emergency poweris typically supplied by means of accumulators, in particular leadaccumulators, so that in the event of a power failure the wind powerinstallation can be put into a position that avoids damage to the windpower installation. For example, in the event of a power failure, whichmay occur due to a short-circuit in the power supply system, leadaccumulators are used to supply the emergency power needed to adjust theblades of the wind power installation, so that the entire wind powerinstallation rotor may be brought to a stop and thereby no longerexperience any substantial drive due to the energy of the wind. In theevent of a power failure, it may also be necessary to rotate the windpower installation pod ‘out of the wind’, in which case, leadaccumulators may also be used as an emergency power supply device toaccomplish this task.

[0005] However, the disadvantage of lead accumulators is that they arerelatively heavy, they take up a great deal of space and, since leadaccumulators cannot be charged and discharged an unlimited number oftimes, the charging and discharging properties of the lead accumulatorsdeteriorate with time. In addition, the storage of a lead accumulatorrequires relatively high maintenance costs and thereby increases thecosts of a wind power installation and operation.

[0006] Elektrizitätswirtschaft, volume 1994 (1995), issue 14, pages 842through 845, disclose various power storage arrangements for supplyingenergy. Also set forth therein are electrical storage means which areused in generating plants, apart from their function as an emergencypower supply, for load compensation purposes and for providing secondsreserves whereby the utilization duration of the energy-generatinginstallations is improved. Double-layer capacitors are also mentioned inthis connection.

[0007] DE 196 51 364 A1 discloses an apparatus for improving the networkcompatibility of wind power installations with asynchronous generators,wherein an electronically controlled device, which includes anintermediate energy storage means, is connected in parallel with thepublic power supply network, and mention is also made of a capacitor asa possible form of the intermediate storage means.

[0008] Despite these disclosures, Applicant believes that there is aneed for a new and improved arrangement for providing emergency power toa wind power installation and the present invention provides suchsystem.

BRIEF SUMMARY OF THE INVENTION

[0009] THE PRESENT INVENTION PROVIDES AN IMPROVED ARRANGEMENT FORSUPPLYING EMERGENCY POWER TO A WIND POWER INSTALLATION. IN THE EVENT OFA POWER FAILURE, SUFFICIENT EMERGENCY POWER MAY BE SUPPLIED TOREPOSITION THE ROTOR BLADES OF THE WIND POWER INSTALLATION AND AVOIDDAMAGE TO THE OVERALL SYSTEM. THIS IS DONE THROUGH THE USE OF ONE ORMORE CAPACITORS. THE CAPACITORS MAY BE CHARGED WITH ENERGY DURING THENORMAL OPERATION OF THE WIND POWER INSTALLATION AND, IN THE EVENT OF ASYSTEM FAILURE, THE ENERGY STORED WITHIN THE CAPACITORS MAY BE USED TOPROVIDE EMERGENCY FUNCTIONS. IN ADDITION TO REPOSITIONING THE ROTORBLADES, THE STORED ENERGY MAY BE USED, FOR EXAMPLE, TO ROTATE THE WINDPOWER INSTALLATION POD AWAY FROM THE WIND AND POWER EMERGENCY ORAUXILIARY LIGHTING SYSTEMS.

BRIEF DESCRIPTION OF THE THE DRAWING(S)

[0010] In the drawings, the sizes and relative positions of elements arenot necessarily drawn to scale. For example, the shapes of variouselements and angles are not drawn to scale, and some of these elementsare enlarged and positioned to improve drawing legibility.

[0011]FIG. 1 is a diagram showing the basic circuitry, according to theprincipals of the present invention, for providing emergency power toadjust the rotor blades of a wind power installation.

DETAILED DESCRIPTION OF THE INVENTION

[0012] According to the principles of the present invention, a capacitoris used to provide electrical energy to a wind power installation andthereby perform various functions.

[0013] The particular advantage of capacitors lies in the freedom frommaintenance and the unlimited number of charging and dischargingprocesses, in contrast to conventional accumulators or batteries.

[0014] Particularly suitable for this purpose is a capacitor produced bySiemens Matsushita Components GmbH & Co KG under the name ‘UltraCap’ andarticle No B48710-A0283-Q035. That capacitor has the following technicaldata: (Nominal) capacitance CR 2.8 F (DCC⁽¹⁾, 25° C.): Capacitancetolerance: −10 . . . +30% (Nominal) voltage UR 75 V Output⁽²⁾ 578 W/kg 765 W/l Max. charging/discharging 25 A current I_(c) (25° C.) Storedenergy (at U_(R)) 7875 J Specific energy (at U_(R)) 1.09 Wh/kg 1.43 Wh/lSurge voltage 88 V Max. leakage current I_(LC) 4 mA (12 h, 25° C.) Max.series resistance ESR^(DC) 800 mΩ (DCC, 25° C. Max. series resistanceESR^(HF) 480 mΩ (1 kHz, 25° C.) Weight 2 kg Volume 1.5 l Operatingtemperature −25 . . . +65° C. Storage temperature −35 . . . +65° C.Service life (25° C., UR) 180,000 h Height × width × length 70 × 70 ×312 mm

[0015]FIG. 1 shows the basic diagram for using one or more capactors 10to adjust the rotor blades of a wind power installation. In thisexample, the rotor of the wind power installation has three rotor blades(not shown) and each individual rotor blade can be set (regulated) to adesired pitch angle via an adjusting motor 12 (A, B or C) couplable toeach individual rotor blade. Each adjusting motor 12 may be controlledby way of a respective relay 14, (A′, B′ or C′).

[0016] A blade regulating device 16 (A″, B″ or C″) is positionedadjacent to the motor 12 and coupled to the capacitor 10. Via relay 14,the blade regulating device 16 receives its values from a control unit18 (control cabinet). In the event of an emergency shut-down, which maybe caused, for example, by a short-circuit in either the wind powerinstallation the power supply device,, the blade regulating device 16effects a blade adjustment which turns each rotor blade out of the wind,so that the rotor blades no longer produce any drive to the rotor.

[0017] The energy required by each blade regulating device 16 isprovided by a capacitor 10 (in this example, CA, CB and CC). Thecapacitors 10 are provided with a connection (not shown) to thegenerator of the wind power installation so that during the normaloperation of a wind power installation, the capacitors 10 receive acharge. In this way, the capacitors 10 are always prepared to provide asufficient amount of energy to set the rotor blades to a desired pitchangle if necessary. Since the capacitors 10 have a very small designconfiguration, they can be positioned directly at the adjusting motorsand can also be held by them. However, it is also possible for allcapacitors 10 to be positioned together in their own accommodation and,if necessary, to be switched on as the emergency power supply device forrotor blade adjustment or for other parts of the wind power installation(for example for alarm lighting or hazard lights).

[0018] Although a single capacitor may be used, it is advantageous toprovide a plurality of capacitors connected in parallel so that asufficient emergency power capacity can always be made available.

[0019] All of the above U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet, areincorporated herein by reference, in their entirety.

[0020] From the foregoing it will be appreciated that, although specificembodiments of the invention have been described herein for purposes ofillustration, various modifications may be made without deviating fromthe spirit and scope of the invention. Accordingly, the invention is notlimited except as by the appended claims.

1. An emergency power supply unit of a wind power installation using acapacitor storage means, wherein an individual rotor blade of the windpower installation or a plurality of rotor blades of the wind powerinstallation are adjustable by means of the emergency power supply unit,wherein an adjusting motor is provided for a rotor blade and thecapacitor storage means is charged up during normal operation of thewind power installation and is positioned at the adjusting motor of arotor blade and the capacitor storage means is coupled to a device forregulating the blade adjustment of the rotor blade.
 2. A method ofgenerating electrical energy in a wind power installation comprising:storing electrical energy in a capacitor during normal operation of awind power installation; and using the electrical energy stored in thecapacitor during a power failure.
 3. The method according to claim 2further comprising: using the energy stored in the capacitor to adjust arotor blade of the wind power installation.
 4. The method according toclaim 2 further comprising: using the energy stored in the capacitor torotate a wind power installation pod.
 5. The method according to claim 2further comprising: using the energy stored in the capacitor to powerauxiliary parts of a wind power installation.
 6. The method according toclaim 2 further comprising: positioning the capacitor adjacent to anadjusting motor; and coupling the capacitor to a blade regulatingdevice.
 7. The method according to claim 2 wherein the capacitorcomprises a plurality of capacitors connected in parallel.
 8. A methodof generating auxiliary power in a wind power installation comprising:positioning a capacitor adjacent to an adjusting motor of a wind powerinstallation; using the motor to charge the capacitor during normaloperation of the wind power installation; using energy stored in thecapacitor to power various components of the wind power installation. 9.A wind power installation having a capacitor positioned adjacent to anadjusting motor of a wind power installation.
 10. The wind powerinstallation according to claim 9 wherein the capacitor is coupled to ablade regulating device.
 11. The wind power installation according toclaim 9 wherein the capacitor is coupled to a lighting system.
 12. Thewind power installation according to claim 9 wherein the capacitorcomprises a plurality of capacitors connected in parallel.